With a valid medical license, radiologists can write prescriptions just like any other physician. After all, you'll have to write scripts for IR patients as well as pre-medication for patients with a contrast allergy. The only catch is that you need a DEA number to write for controlled substances.
Of course, my medical license says that I'm allowed to perform medicine and surgery in my state, but that doesn't mean I'm going to take out someone's appendix. Be careful not to start writing for unfamiliar meds, or you could get into trouble. As years go by, all that pharmacology in your brain will vaporize, and you may feel less comfortable writing even simple scripts.
